Beta2-glycoprotein I Research Articles

Serum apolipoprotein H determines ferroptosis resistance by modulating cellular lipid composition

Ferroptosis is a regulated cell death process dependent on iron, triggered by the accumulation of lipid peroxidation. The environmental context significantly impacts cellular sensitivities to ferroptosis. Serum, constituting the extracellular fluid composition in vivo, provides crucial environmental biomolecules. In this study, we investigated the influence of sera on ferroptosis induction, pinpointing the serum protein apolipoprotein H (APOH) as a pivotal inhibitor of ferroptosis. Moreover, we elucidated that APOH suppresses ferroptosis by activating the phosphoinositide 3-kinase (PI3K)-AKT-sterol regulatory element-binding proteins (SREBPs) pathway, thereby elevating stearoyl-CoA desaturase (SCD) levels and augmenting cellular monounsaturated fatty acid-containing phospholipids (MUFA-PLs). Furthermore, ApoHinfer, the peptide derivative of the active region of APOH, mimics its ferroptosis inhibitory activity. Our findings underscore the critical role of serum protein APOH in the inhibition of ferroptosis and indicates potential therapeutic applications in treating cancer and diseases associated with ferroptosis.

Right Ventricular Outflow Tract Mass as the Initial Presentation of Primary Antiphospholipid Syndrome

Abstract Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by the presence of antiphospholipid antibodies and clinical manifestations, including thrombosis and pregnancy-related complications. While cardiac manifestations such as intracardiac thrombi, valvular disease, and intracardiac masses have been reported, the presentation of an intracardiac mass as the initial manifestation of primary APS (PAPS) is relatively uncommon. This case report describes a 40-year-old female patient who presented with an echogenic mass in the right ventricular outflow tract, subsequently diagnosed as a calcified amorphous tumor. Further investigation revealed elevated levels of anticardiolipin antibodies and beta-2 glycoprotein leading to the diagnosis of PAPS. The patient later developed digital ischemia, strengthening the suspicion of PAPS. This case highlights the importance of considering APS as a potential underlying cause for intracardiac masses, even in the absence of other typical manifestations. Early recognition and appropriate management, including anticoagulation and immunosuppressive therapy, are crucial to prevent further thrombotic complications and improve patient outcomes.

Domain 5 of Beta 2 glycoprotein I: Friend or foe in health? Context matters

Beta 2 glycoprotein I (β2GPI) is the major autoantigen in the antiphospholipid syndrome, an autoimmune disorder characterized by thrombotic and obstetric complications. The autoantibodies that target beta 2 glycoprotein I are pathogenic and contribute to disease pathogenesis. The β2GPI molecule is composed of 5 domains that are numbered 1 through to 5. Autoantibodies bind mainly to domain 1 whereas the majority of the biological functions of the β2GPI molecule in diverse processes such as apoptotic cell clearance, complement regulation, lipopolysaccharide clearance and anticoagulation have been localised to domain 5 and its unique biochemistry, reviewed in this article. The role of purified domain 5 peptide as a potential therapeutic agent in APS and ischemia reperfusion injury is discussed.

Apolipoprotein H-based prognostic risk correlates with liver lipid metabolism disorder in patients with HBV-related hepatocellular carcinoma

Background/Aim: Chronic hepatitis B patients often develop concomitant fatty liver disease, which is associated with increased risk of liver cirrhosis and hepatocarcinoma. Our previous studies have shown that apolipoprotein H (APOH) levels are gradually decreased in patients with chronic HBV infection at different stages of disease progression, and APOH deficiency disrupted hepatic lipid metabolism and caused fatty liver. We focus on the relationship between APOH and hepatocellular carcinoma (HCC) in the context of chronic HBV infection. Methods and resultsAPOH was downregulated at the transcriptional level in HBV-related HCC patients from open-source human liver transcriptome databases, and relatively high expression of APOH might be a favourable prognostic marker in HCC. APOH downregulation was positively associated with tumour grade and HCC subtypes. The analysis result of CHCC-HBV database showed that APOH-associated differential expression genes (DEGs) enriched in lipid metabolic pathways and downregulated APOH correlated with macrophage, neutrophil and CD8 T cell infiltration levels. Next, in vitro experiments were performed and APOH gene was silenced in HepG2.2.15 cells, an HBV producing human HCC cells. Further transcriptomic assay and analysis revealed the DEGs were enriched in cholesterol metabolism. The subsequent RT-qPCR experiments identified that CYP7A1 expression was higher upregulated in APOH silencing HepG2.2.15 cells than vehicle control cells (p < 0.05). Finally, demographic data of patients with HBV-related HCC were enrolled, and serum APOH levels were analysed using ELISA. Serum APOH levels were significantly lower in patients with HCC than in healthy controls (p < 0.05), and positively correlated with triglyceride level in healthy controls (p < 0.05). In HBV-HCC patients, serum APOH levels were positively correlated with albumin levels and negatively correlated with alkaline phosphatase (ALP), total bilirubin, and INR levels (p < 0.05). ConclusionAPOH downregulation disrupted liver lipid metabolism to potentially affect the overall survival in patients with HBV-related HCC.

The protective effect of apolipoprotein H in paediatric sepsis

BackgroundSepsis is a severe condition characterized by acute organ dysfunction resulting from an imbalanced host immune response to infections. Apolipoprotein H (APOH) is a critical plasma protein that plays a crucial role in regulating various biological processes. However, the precise role of APOH in the immunopathology of paediatric sepsis remains unclear.MethodsIn this study, we evaluated the concentration of APOH in paediatric patients with sepsis and healthy individuals. In an experimental sepsis model of caecal ligation and puncture (CLP), the impact of APOH on survival, organ injury, and inflammation was measured. Furthermore, the anti-inflammatory effects of APOH were investigated across diverse immune cell types, encompassing peripheral blood mononuclear cells (PBMCs), peritoneal macrophages (PMs), bone marrow-derived macrophages (BMDMs), and RAW 264.7 macrophages.ResultsIn the pilot cohort, the relative abundance of APOH was found to be decreased in patients with sepsis (2.94 ± 0.61) compared to healthy controls (1.13 ± 0.84) (p < 0.001), non-survivors had lower levels of APOH (0.50 ± 0.37) compared to survivors (1.45 ± 0.83) (p < 0.05). In the validation cohort, the serum concentration of APOH was significantly decreased in patients with sepsis (202.0 ± 22.5 ng/ml) compared to healthy controls (409.5 ± 182.9 ng/ml) (p < 0.0001). The application of recombinant APOH protein as a therapeutic intervention significantly lowered the mortality rate, mitigated organ injury, and suppressed inflammation in mice with severe sepsis. In contrast, neutralizing APOH with an anti-APOH monoclonal antibody increased the mortality rate, exacerbated organ injury, and intensified inflammation in mice with non-severe sepsis. Intriguingly, APOH exhibited minimal effects on the bacterial burden, neutrophil, and macrophage counts in the sepsis mouse model, along with negligible effects on bacterial phagocytosis and killing during Pseudomonas aeruginosa infection in PMs, RAW 264.7 cells, and PBMCs. Mechanistic investigations in PMs and RAW 264.7 cells revealed that APOH inhibited M1 polarization in macrophages by suppressing toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signalling pathway.ConclusionThis proof-of-concept study demonstrated that APOH has a protective role in the host defense response to sepsis, highlighting the potential therapeutic value of APOH in sepsis treatment.Graphical abstract

Effects of apolipoprotein H downregulation on lipid metabolism, fatty liver disease, and gut microbiota dysbiosis

Apolipoprotein H (APOH) downregulation can cause hepatic steatosis and gut microbiota dysbiosis. However, the mechanism by which APOH-regulated lipid metabolism contributes to metabolic dysfunction–associated steatotic liver disease (MASLD) remains undetermined. Herein, we aim to explore the regulatory effect of APOH, mediated through various pathways, on metabolic homeostasis and MASLD pathogenesis. We analyzed serum marker levels, liver histopathology, and cholesterol metabolism–related gene expression in global ApoH−/− C57BL/6 male mice. We used RNA sequencing and metabolomic techniques to investigate the association between liver metabolism and bacterial composition. Fifty-two differentially expressed genes were identified between ApoH−/− and WT mice. The mRNA levels of de novo lipogenesis genes were highly upregulated in ApoH−/− mice than in WT mice. Fatty acid, glycerophospholipid, sterol lipid, and triglyceride levels were elevated, while hyodeoxycholic acid levels were significantly reduced in the liver tissues of ApoH−/− mice than in those of WT mice. Microbial beta diversity was lower in ApoH−/− mice than in WT mice, and gut microbiota metabolic functions were activated in ApoH−/− mice. Moreover, ApoH transcripts were downregulated in patients with MASLD, and APOH-related differential genes were enriched in lipid metabolism. Open-source transcript-level data from human metabolic dysfunction–associated steatohepatitis livers reinforced a significant association between metabolic dysfunction–associated steatohepatitis and APOH downregulation. In conclusion, our studies demonstrated that APOH downregulation aggravates fatty liver and induces gut microbiota dysbiosis by dysregulating bile acids. Our findings offer a novel perspective on APOH-mediated lipid metabolic dysbiosis and provide a valuable framework for deciphering the role of APOH in fatty liver disease.

Clinical Characteristics and Anticoagulation Use in Antiphospholipid Syndrome: A Single-Center Retrospective Analysis

Background: Warfarin remains the anticoagulant of choice for patients with antiphospholipid syndrome (APLS). However, conflicting data exists regarding the role of direct oral anticoagulants (DOACs) as reasonable alternatives to warfarin, which has a less desirable side effect profile. In clinical practice, some patients start taking DOACs or aspirin before an official APLS diagnosis is confirmed and these patients may choose to continue a DOAC after an informed discussion with their hematologist. To gain a better understanding of anticoagulant use in APLS at our center, we conducted a retrospective study to assess the clinical characteristics of patients diagnosed with APLS. Methods: All patients with an ICD-10 code indicating APLS from January of 2020 to April of 2023 were included. Patient characteristics, relevant laboratory testing (lupus anticoagulant, beta-2 glycoprotein IgG/IgM, and anti-cardiolipin IgG/IgM), and treatment history were extracted from the electronic medical record. Patients were deemed to have single positivity if any one of the following were present: detectable lupus anticoagulant, elevated (defined as &amp;gt;40 GPL) beta-2 glycoprotein (B2GP) IgG or IgM, or elevated cardiolipin IgG or IgM both on initial and confirmatory testing (performed approximately 12 weeks later). Similarly, double positivity was defined as the presence of two of these biomarkers and triple positive was defined as the presence of three of these biomarkers. Initial laboratory testing results are included in Table 1. Statistical analysis was conducted using the SAS software (SAS Enterprise Guide 7.1) and the R Core Team (R 4.2.2). Continuous variables such as BMI and age were evaluated using the Wilcoxon rank-sum test, while categorical variables were assessed using Fisher's Exact Test and Chi-squared test. Results: Seventy-two patients were included in our analysis. Mean age and BMI were 56.3 ± 16.8 years and 32.3 ± 11.2, respectively. The majority of patients were female (69.4%) and white (83.8%). Approximately half of all patients had single positivity (64.4%) and more than half had detectable lupus anticoagulant (58.7%). Cardiolipin IgM was the most frequently (36.1%) elevated biomarker. Patient characteristics between the DOAC/aspirin and warfarin/enoxaparin cohorts were not significantly different; however, significantly more patients with single positivity received DOAC/Aspirin rather than warfarin/enoxaparin (77.8% vs.43.5%, p = 0.012). There was no statistically significant difference between the frequency of arterial complications in patients who took DOAC/Aspirin (4 events in 39 patients) versus those who took warfarin/enoxaparin (1 event in 33 patients), p = 0.366. The majority of arterial complications (4 of 5 events) occurred in patients with double and triple positivity. In addition, a logistical regression was performed regarding different characteristic effects on positivity level (single, double or triple laboratory positive), which found the presence of lupus anticoagulant had a significant association with higher likelihood of double/triple positivity (p = 0.048). Conclusion: This study provides potential reassurance for clinicians regarding the use of DOACs during the investigative phase of APLS and supports the continuation of DOAC therapy in patients, particularly those with single positivity, after careful evaluation and shared decision-making with patients. However, caution should be kept when considering DOAC use in patients with lupus anticoagulant, double, or triple positivity, due to concerning arterial events. Further large multi-center randomized clinical trials are necessary in the future to clarify the role of DOACs in APLS.

Hematological Manifestations of Antiphospholipid Antibodies: A Case Series from South India

Introduction: Antiphospholipid syndrome (APS) is known for its association with unexplained vascular thrombosis and pregnancy-related complications. However, APS can also present with various hematological abnormalities, including thrombocytopenia, autoimmune hemolytic anemia, Evan's syndrome, and thrombotic microangiopathy. While APS is often considered in patients with these manifestations, its laboratory testing yield and patterns in hematology clinics remain underexplored. In this study, we aimed to investigate the prevalence of laboratory positivity for APS in patients attending hematology clinics, even in the absence of meeting the clinical criteria for APS. Methodology: This retrospective study was conducted at two tertiary care centers in southern India from January 2018 to June 2023. Patients who visited hematology clinics and underwent APS workup were included. The APS workup involved evaluating Anti Cardiolipin IGG and IGM, Anti Beta2 Glycoprotein IGG and IGM, Lupus Anticoagulant, and ANA. The laboratory criteria for APS were based on the ACR/EULAR APS Criteria. Patients with transiently positive results were excluded from the study. Chi Square test was used for statistical analysis. Results: Among the 624 patients who underwent APS workup, 100 patients (16.03%) tested positive for at least one of the laboratory criteria for APS. Remarkably, a significant proportion (56%)of these patients did not fulfill the clinical criteria for APS. The most common hematological manifestations prompting APS testing in these 100 patients were thrombocytopenia (38%) and unprovoked thrombosis (35%). Additional hematological abnormalities included autoimmune hemolytic anemia (13%), prolonged activated partial thromboplastin time (APTT) (5%), Evan's syndrome (4%), pancytopenia (4%), and thrombotic thrombocytopenic purpura (TTP) (1%). Baseline characterstics of our study subjects are shown in Table 1 Anti-beta2 glycoprotein IGG or IGM antibodies were detected in 74% of APS-positive patients, and Anti-cardiolipin IGG or IGM antibodies were found in 57%. Lupus Anticoagulant (LA) was present in 59%. Additionally, 28% of the patients showed positivity for all three antibodies, indicating a significant overlap in laboratory findings. No statistically significant difference in antibody positivity patterns was observed between patients satisfying the clinical criteria for APS and those without, as shown in Table 2 Conclusion: Our study sheds light on the hematological presentations of APS in patients attending hematology clinics in southern India. Importantly, a substantial number(56%)of patients with APS lab test positivity did not meet the clinical criteria for APS. These findings emphasize the importance of considering APS as a potential diagnosis in patients presenting with hematological manifestations, especially thrombocytopenia and autoimmune hemolytic anemia. Identifying APS in such cases can guide appropriate therapeutic interventions and may help prevent pregnancy-related complications in affected females. Raising awareness among healthcare professionals about the diverse hematological presentations of APS is vital for improving patient outcomes and ensuring timely and accurate diagnoses

Identification of the key immune-related genes and immune cell infiltration changes in renal interstitial fibrosis.

Chronic kidney disease (CKD) is the third-leading cause of premature mortality worldwide. It is characterized by rapid deterioration due to renal interstitial fibrosis (RIF) via excessive inflammatory infiltration. The aim of this study was to discover key immune-related genes (IRGs) to provide valuable insights and therapeutic targets for RIF in CKD. We screened differentially expressed genes (DEGs) between RIF samples from CKD patients and healthy controls from a public database. Least absolute shrinkage and selection operator regression analysis and receiver operating characteristic curve analysis were applied to identify significant key biomarkers. The single-sample Gene Set Enrichment Analysis (ssGSEA) algorithm was used to analyze the infiltration of immune cells between the RIF and control samples. The correlation between biomarkers and immune cell composition was assessed. A total of 928 DEGs between CKD and control samples from six microarray datasets were found, 17 overlapping immune-correlated DEGs were identified by integration with the ImmPort database, and six IRGs were finally identified in the model: apolipoprotein H (APOH), epidermal growth factor (EGF), lactotransferrin (LTF), lysozyme (LYZ), phospholipid transfer protein (PLTP), and secretory leukocyte peptidase inhibitor (SLPI). Two additional datasets and in vivo experiments indicated that the expression levels of APOH and EGF in the fibrosis group were significantly lower than those in the control group, while the expression levels of LTF, LYZ, PLTP, and SLPI were higher (all P < 0.05). These IRGs also showed a significant correlation with renal function impairment. Moreover, four upregulated IRGs were positively associated with various T cell populations, which were enriched in RIF tissues, whereas two downregulated IRGs had opposite results. Several signaling pathways, such as the "T cell receptor signaling pathway" and "positive regulation of NF-κB signaling pathway", were discovered to be associated not only with immune cell infiltration, but also with the expression levels of six IRGs. In summary, six IRGs were identified as key biomarkers for RIF, and exhibited a strong correlation with various T cells and with the NF-κB signaling pathway. All these IRGs and their signaling pathways may evolve as valuable therapeutic targets for RIF in CKD.

Antiphospholipid Antibody Syndrome (APS) Pediatric Patient Outcomes on Warfarin

Background: Antiphospholipid antibody syndrome (APS) is an acquired thromboembolism (TE) risk factor and places patients at very high risk of recurrent TE. APS diagnosis requires venous (deep vein thrombosis (DVT) or pulmonary embolism (PE)) or arterial thromboembolism and laboratory diagnosis including persistently positive lupus anticoagulant (LA) or elevated anticardiolipin (aCL) and/or beta 2 glycoprotein I (B2GPI) antibodies tested 12 weeks apart. Vitamin K antagonist (warfarin) is the standard of care anticoagulant to reduce risk of TE recurrence in APS patients. Warfarin is dosed based on the International Normalized Ratio (INR) with established therapeutic ranges for optimal efficacy and safety. The reported time in therapeutic range (TTR) varies greatly across specialties with an average TTR of 50-55%. However, it is often difficult to maintain target INR in APS. Furthermore, there is limited data evaluating pediatric patients with APS and their TTR on warfarin and outcomes. Aim: To evaluate the relationship of APS status to TTR and outcomes of patients &amp;lt; 21 years of age with APS who are on warfarin anticoagulation. Methods: This was a single center analysis of APS patients between July 2019 and May 2022 who were enrolled in a multi-center prospective study of pediatric patients on warfarin therapy, eKITE (electronic KidClot Thrombophilia Education). The study included an online learning series regarding warfarin management. Home INR meters and test strips were provided to all patients to perform INR testing. INR values were reported by patients and recorded. Demographic and clinical data was extracted from the electronic medical record, target INR was set by the treating provider, and TTR was calculated as a surrogate for safe, effective warfarin management. Results: Nine patients (n=9) with APS were identified for this analysis, mean age 16.7 years (range 12-19 years). Demographic and laboratory findings are summarized in Table 1. Most patients had secondary APS due to systemic lupus erythematous (SLE) 78% (n=7) and 22% (n=2) had other primary diagnoses. APS antibody status included single positive in 67% (n=6), double positive in 22% (n=2), and triple positive in 11% (n=1). More specifically, APS criteria were met by persistently elevated LA in 78% (n=7), aCL IgM in 22% (n=2) with overall mean aCL IgM of 34.4 MPL^ (range 9.9-127.9), B2GPI IgG in 11% (n=1) with overall mean B2GPI IgG SGU* of 13.1 (range 0.9-63.3), and B2GPI IgM in 22% (n=2) with overall B2GPI IgM mean of 32.5 SGU (range 3.3-190.9). At time of presentation 67% (n=6) of patients had DVT, 44% (n=4) had PE, 11% (n=1) had arterial TE, and 22% (n=2) presented with DVT &amp; PE. Mean TTR for all patients was 56%. TTR for single positive APS was 66%, double positive APS 39%, and triple positive APS 33%. TTR for secondary APS (SLE) and non-SLE diagnoses was 53% and 68% respectively. Mean dose changes were 11 (range 0-48) with one single positive LA patient requiring 48 dose changes, and two patients with single positive LA not requiring any dose changes. Two patients (22%) developed recurrent clot. One triple positive APS patient developed two DVTs and one non-SLE patient developed recurrent arterial TE. Three patients (33%) had minor bleeding events including mild epistaxis and hematemesis not requiring intervention. One patient (11%) had a major bleeding event, hemoperitoneum from pseudoaneurysm extravasation, while resuming warfarin during post-operative period, and required takeback surgery with sub-therapeutic INR 1.5 at the time of event. Conclusion: The mean TTR for pediatric patients with APS is similar to what is reported in other populations despite the challenge of managing warfarin in this group where the INR may be affected by primary disease modifying medications or disease flares. The risk of recurrent TE remains high in APS patients. Home INR monitors are a safe and effective strategy in managing warfarin anticoagulation in APS patients, reducing time and laboratory monitoring burden for frequent dose changes, which ultimately improves quality of life.Optimizing TTR is important to decrease risk of recurrent TE or bleeding in these high risk APS patients.

HTRS2023.P4.11 Platelet-associated beta-2 glycoprotein 1 inhibits agonist-induced platelet activation which is relieved by proteolytic cleavage

HTRS2023.P4.11 Platelet-associated beta-2 glycoprotein 1 inhibits agonist-induced platelet activation which is relieved by proteolytic cleavage

Interaction of the antiphospholipid syndrome autoantigen beta-2 glycoprotein I with DNA and neutrophil extracellular traps

Beta-2 glycoprotein I (β2GPI) is a phospholipid-binding plasma protein and prominent autoantigen in antiphospholipid syndrome (APS). Here, we tested the hypothesis that β2GPI might bind to not only phospholipids, but also cell-free DNA and neutrophil extracellular traps (NETs). We report that β2GPI interacts with cell-free DNA from different species, as well as NETs, in a dose-dependent manner, retarding their migration in an agarose-gel electrophoretic mobility shift assay. We confirm the direct binding interaction of β2GPI with DNA and NETs by ELISA. We also demonstrate that β2GPI colocalizes with NET strands by immunofluorescence microscopy. Finally, we provide evidence that β2GPI-DNA complexes can be detected in the plasma of APS patients, where they positively correlate with an established biomarker of NET remnants. Taken together, our findings indicate that β2GPI interacts with DNA and NETs, and suggest that this interaction may play a role as a perpetuator and/or instigator of autoimmunity in APS.

Rapidly Resolving Orbital Pseudotumor in Systemic Lupus Erythematosus

Rapidly Resolving Orbital Pseudotumor in Systemic Lupus Erythematosus

Cerebral Vasculitis in a patient receiving Risankizumab, an Inhibitor of Interleukin-23: First Case Report (P12-3.013)

<h3>Objective:</h3> NA <h3>Background:</h3> Iatrogenic neuroinflammation has been frequently reported in recent years owing to expanding biologic therapies for the treatment of a wide range of disorders including Psoriasis. Here we report a case of Central Nervous System (CNS) vasculitis after initiation of Risankizumab, a monoclonal antibody against Interleukin-23 (IL23) used to treat Psoriasis. <h3>Design/Methods:</h3> Case report. <h3>Results:</h3> A 29-year-old female with moderate psoriasis who was started on Risankizumab about one month prior, presented with encephalopathy and left temporal lobe focal seizures with refractory status epilepticus. Her MRI showed punctate infarcts and areas of enhancement in the left temporal lobe and leptomeninges overlying the left convexity. Extensive work up revealed increased Erythrocyte Sedimentation Rate (72 mm/hr) and positive Cardiolipin (IgM and IgG) and Beta-2 Glycoprotein (IgM and IgG) antibodies suggesting antiphospholipid syndrome (APS) for which she was started on anticoagulation. Lumbar puncture revealed normal opening pressure, glucose, protein and five nucleated cells. Oligoclonal bands, meningitis/encephalitis and autoimmune encephalitis panels were negative. Subsequent brain MRI showed new areas of ischemic lesions. Cerebral angiogram was unremarkable. Biopsy revealed focal perivascular lymphocytes (CD45 and CD3 immunohistochemical stained) infiltration in dural vessels consistent with small-vessel vasculitis. She was treated with high dose steroids with clinical improvement and subsequently planned to treat with Cyclophosphamide. Risankizumab was discontinued due to possible association. <h3>Conclusions:</h3> Iatrogenic neuroinflammation has been increasingly recognized during the new era of biological molecules and monoclonal antibodies for systemic inflammatory disorders and malignancies. Tumor necrosis factor inhibitors and immune checkpoint inhibitors are more commonly associated with neuroinflammation. To the best of our knowledge, this is the first reported case of APS and CNS vasculitis possibly associated with the initiation of IL23 inhibitor Risankizumab. Although causality cannot be established with a single case, it suggests a possible association. <b>Disclosure:</b> Dr. Cabrera Pulla has nothing to disclose. Dr. Amirjanyan has nothing to disclose. Qian Wu has nothing to disclose. Dr. Mui has nothing to disclose. Dr. Imitola has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novartis . The institution of Dr. Imitola has received research support from biogen. Dr. Imitola has a non-compensated relationship as a Board Member with National MS Society that is relevant to AAN interests or activities. Dr. Imitola has a non-compensated relationship as a Committee Member with International Society for Stem Cell Research that is relevant to AAN interests or activities. Dr. Coban has nothing to disclose.

Prevalence of Antiphospholipid Antibodies and Association With Incident Cardiovascular Events

The prevalence of antiphospholipid antibodies (aPL) and their association with future atherosclerotic cardiovascular disease (ASCVD) risk has yet to be thoroughly investigated. To determine the association between measurements of aPL at a single time point and ASCVD risk in a diverse population. This cohort study measured 8 aPL (anticardiolipin [aCL] IgG/IgM/IgA, anti-beta-2 glycoprotein I [aβ2GPI] IgG/IgM/IgA, and antiphosphatidylserine/prothrombin [aPS/PT] IgG/IgM) by solid-phase assays in plasma from participants of the Dallas Heart Study (DHS) phase 2, a multiethnic, population-based cohort study. Blood samples were collected between 2007 and 2009. The median follow-up was 8 years. Statistical analysis was performed from April 2022 to January 2023. Associations of aPL with future ASCVD events (defined as first nonfatal myocardial infarction, first nonfatal stroke, coronary revascularization, or death from cardiovascular cause) were assessed by Cox proportional hazards models, adjusting for known risk factors, medications, and multiple comparisons. Among the 2427 participants (mean [SD] age, 50.6 [10.3] years; 1399 [57.6%] female; 1244 [51.3%] Black, 339 [14.0%] Hispanic, and 796 [32.8%] White), the prevalence of any positive aPL tested at a single time point was 14.5% (353 of 2427), with approximately one-third of those detected at a moderate or high titer; aCL IgM had the highest prevalence (156 individuals [6.4%]), followed by aPS/PT IgM (88 [3.4%]), aβ2GPI IgM (63 [2.6%]), and aβ2GPI IgA (62 [2.5%]). The IgA of aCL (adjusted hazard ratio [HR], 4.92; 95% CI, 1.52-15.98) and aβ2GPI (HR, 2.91; 95% CI, 1.32-6.41) were independently associated with future ASCVD events. The risk further increased when applying a positivity threshold of at least 40 units (aCL IgA: HR, 9.01 [95% CI, 2.73-29.72]; aβ2GPI IgA: HR, 4.09 [95% CI, 1.45-11.54]). Levels of aβ2GPI IgA negatively correlated with cholesterol efflux capacity (r = -0.055; P = .009) and positively correlated with circulating oxidized LDL (r = 0.055; P = .007). aβ2GPI IgA-positive plasma was associated with an activated endothelial cell phenotype as evidenced by increased surface expression of surface E-selectin, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1. In this population-based cohort study, aPL detectable by solid-phase assays were present in a substantial proportion of adults; positive aCL IgA and aβ2GPI IgA at a single time point were independently associated with future ASCVD events. Longitudinal studies with serial aPL measurements are needed to further explore these findings.

Association between Inflammation and Thrombotic Pathway Link with Pathogenesis of Depression and Anxiety in SLE Patients.

As a complication of systemic lupus erythematosus (SLE), the neuropsychiatric form may manifest with neurological and psychiatric symptoms. Diagnosing neuropsychiatric SLE can be challenging due to the heterogeneity of this disease manifestation and the possibilities of investigation. This research aims to identify the possible associations between inflammation and thrombotic biomarkers alongside anxiety and/or depression manifestations in SLE patients. A group of 65 outpatients were investigated regarding the levels of depression, anxiety, disability, quality of life and other specific serum biomarkers linked with inflammation or coagulopathies. The results showed severe depression in eight participants, moderate depression in 22 (33.85%), and 26 (40%) subjects with mild depression. Anxiety was more prevalent within 64 participants (98.46%), while a degree of disability was reported by 52 participants (80%). Quality of life evaluated by EQ5D revealed a medium value of 1.57, and EQ5D VAS health medium value was 57.95 and was correlated with anxiety. A strong positive correlation between depression, anxiety and antibodies associated with anti-cardiolipin and anti beta2 glycoprotein I antibodies, lupus anticoagulant, ICAM-1, low C4 a and anti-ribosomal P antibodies were identified. These data results suggest that autoimmune/inflammatory and ischemic/thrombotic pathways could contribute to depression and anxiety as neuropsychiatric SLE manifestations.

Apolipoprotein H induces sex-specific steatohepatitis and gut dysbiosis during chronic hepatitis B infection

Apolipoprotein H (APOH) is involved in lipid metabolism and functions as an acute-phase protein during hepatitis B virus (HBV) infection. Herein, we explored whether APOH acts on the development of fatty liver upon chronic HBV infection. Serum APOH level was significantly lower in cirrhosis patients than in healthy controls or patients with chronic infection. It showed sex bias, with elevated levels in female patients with chronic infection. Also, serum APOH levels were negatively correlated with HBV surface antigen (HBsAg) but positively correlated with albumin and triglyceride levels. In Invitro HBV infection model, HBV upregulated APOH expression in a non-temporal manner, and HBsAg levels were elevated by silencing APOH. RNA sequencing (RNA-seq) demonstrated bidirectional expression of APOH, which impacted the immunoregulation upon infection or the metabolic regulation in HepG2.2.15 cells. Then, ApoH -/- mice with persistent HBV replication displayed steatohepatitis and gut microbiota dysbiosis with synergistic sex differences. Our study deciphers the roles of APOH in chronic liver diseases.

Abstract TP175: Age And Malignancy Associated With Positive Antiphospholipid Antibody Testing And Diagnosis In Embolic Stroke Of Undetermined Source Patients: A Retrospective Cohort Study

Introduction: Embolic stroke of undetermined source (ESUS) is a clinical paradigm that helps to classify and lead investigations into cryptogenic stroke. Diagnostic evaluation of ESUS involves investigating several potential etiologies of stroke. One such etiology includes antiphospholipid syndrome (APLS), a syndrome known to cause hypercoagulability. Clinical characteristics of primary APLS in ESUS have not been described. Methods: This is an IRB approved, retrospective study including patients from 2015-2020 who were seen at Mayo Clinic, were diagnosed with ESUS, and had APLS testing (anti-cardiolipin, beta-2 glycoprotein, or lupus anticoagulant). Baseline characteristics and radiographic features were collected and compared between patients who were and were not diagnosed with APLS, as well as between patients who were and were not APLS antibody positive. Results: Our study included 206 patients. Positive APLS antibody testing was seen in 21 (10%) patients. Of those patients, 8 (4%) received a formal diagnosis of APLS. Compared to controls, patients with positive APLS antibodies as well as those diagnosed with APLS were more likely to have a history of cancer (20 [11%] APLS antibody negative vs 7 [33%] APLS antibody positive p=0.004) (23 [12%] APLS diagnosis negative vs 4 [50%] APLS diagnosis p=0.002). Mean age in primary APLS was greater, 57 years old APLS antibody negative vs 69 years old APLS antibody positive (p&lt;0.001) and 58 years old APLS diagnosis negative vs 75 years old APLS diagnosis (p=0.001) (Table 1). Regressions analyses examining infarct topography and rate of hemorrhagic transformation were non-significant between groups (p&gt;0.1) Conclusion: APLS presenting as ESUS is associated with older age and history of malignancy. We speculate this finding may underscore the need to consider hypercoagulable conditions more broadly in stroke evaluations of older populations. Larger cohorts and longer follow up will be required to validate this observation.

Longitudinal efficacy and toxicity of SARS-CoV-2 vaccination in cancer patients treated with immunotherapy

Despite more than 2 years having elapsed since the onset of SARS-CoV-2 pandemic, a level of hesitation around increased SARS-CoV-2 vaccine toxicity in cancer patients receiving immunotherapy (IO) remains. This hesitation stems from the idea that IO agents could elicit an overwhelming immune stimulation post vaccination and therefore increase the risk of vaccine-related toxicity. The aim of our study was to explore serological responses to SARS-CoV-2 vaccination in patients treated with IO and describe the level of immune stimulation using parameters such as blood cytokines, autoantibody levels and immune related adverse events (irAEs) post vaccination. Fifty-one evaluable patients were enrolled in this longitudinal study. Absolute levels and neutralization potential of anti-SARS-CoV-2 antibodies were not significantly different in the IO group compared to non-IO. Chemotherapy adversely affected seroconversion when compared to IO and/or targeted treatment. Following vaccination, the prevalence of grade ≥2 irAEs in patients treated with IO was not higher than the usual reported IO toxicity. We report, for the first time, that anti-SARS-CoV-2 vaccination, elicited the generation of five autoantibodies. The significantly increased autoantibodies were IgM autoantibodies against beta-2 glycoprotein (p = 0.02), myeloperoxidase (p = 0.03), nucleosome (p = 0.041), SPLUNC2 (p < 0.001) and IgG autoantibody against Myosin Heavy Chain 6 (MYH6) (p < 0.001). Overall, comprehensive analysis of a small cohort showed that co-administration of SARS-CoV-2 vaccine and IO is not associated with increased irAEs. Nevertheless, the detection of autoantibodies post anti-SARS-CoV-2 vaccination warrants further investigation (NCT03702309).

A Case Series of Immune Flare and Lupus Anticoagulant Following COVID-19 Vaccination

Background: Vaccination against COVID-19 has garnered concerns for unusual post-vaccination complications. We present 2 cases of immune flare following COVID-19 vaccination. Case Report: Our first patient was a 53-year-old male who presented with a swollen left leg, hypoxia and palpitations after a trans-Atlantic flight. Chest computed tomography showed bilateral subsegmental pulmonary emboli, with no evidence of right heart strain and Doppler ultrasonography of the lower extremities showed significant clot burden in the left femoral, popliteal, tibial and peroneal veins. Workup revealed thrombocytopenia of 81,000/μL (normal range [NR] 150,000-450,000/μL), elevated D-dimer of 6.25 μg/ml (NR < 0.5 μg/ml), elevated partial thromboplastin time at 94 seconds without heparin. Mixing studies corrected partially to 60.9 seconds (NR 22.5-39.4), indicating the presence of an inhibitor, and lupus anticoagulant was confirmed with dilute Russell viper venom ratio of 3.66 (NR 0.00-1.20) and silica clotting time ratio of 3.95 (NR 0.00-1.22). Anti-beta-2 glycoprotein and anti-cardiolipin antibodies, factor V Leiden mutation, prothrombin G20210A mutation, protein C and protein S were negative. He received 2 doses of the ChAdOx1 nCoV-19 adenoviral vaccine 6 weeks previously. Due to suspicion for vaccine-induced thrombotic thrombocytopenia, enzyme-linked immunoassay for anti-platelet-factor 4 antibody was tested, which was negative. Immediate anticoagulation therapy with low-molecular weight heparin was started and then switched to rivaroxaban. Our second patient was an 18-year-old male who presented with 2 weeks of right-sided lower chest pain. The cardiopulmonary workup was negative, with a computed tomography of the chest showing a borderline enlarged spleen at 13 cm, and hepatic steatosis. He was taking indomethacin for slipped rib pain and was less mobile than usual. One week later, he developed left posterior thigh pain extending down the posterior calf and was found to have totally occluding left leg deep venous thrombosis from femoral vein mid to distal, popliteal, posterior tibial, peroneal, gastrocnemius and soleal veins. Workup was significant for prolonged partial thromboplastin time at 78 seconds, which partially corrected to 62 seconds with mixing studies, elevated C-reactive protein of 5.4, positive antinuclear antibodies (1:1280), normal complement (C3 and C4) and negative RF, SS A/Ro, SS B/La, RNP, smooth muscle, LKM antibodies. He started anticoagulation with low-molecular weight heparin, which was transitioned to apixaban. His family history was significant for lupus in his aunt and grandmother; however, there was no family history of thrombosis. He had received the third mRNA COVID vaccine 2 weeks prior to presentation. Additional workup revealed positive lupus anticoagulant, beta-2 glycoprotein, cardiolipin antibodies, and he was started on warfarin with a target international normalized ratio of 2-3 and repeat testing 3 months later revealed persistent elevation, indicating antiphospholipid syndrome. Although there was low suspicion for vaccine induced thrombotic thrombocytopenia, heparin-induced thrombocytopenia panel was performed and was negative. Discussion: Multiple SARS-CoV-2 vaccines were rapidly developed and approved, but long-term effects are unknown. Recombinant adenoviral vector-based vaccines raised concerns for an unusual post-vaccination coagulopathic syndrome with anti-platelet-factor 4 antibodies seen in 90% of probable and definite cases of vaccine-induced thrombotic thrombocytopenia (Pavord et al). Positive lupus anticoagulant has been noted with severe COVID-19 (Tung et al); however, our first patient had no history of COVID-19. This presentation was attributed at the time to a pro-inflammatory state induced by vaccination that may have caused lupus anticoagulant titers to rise leading to thrombosis as seen in this case. Autoimmune manifestations after COVID-19 vaccination are thought to be due to molecular mimicry, autoantibodies, vaccine adjuvants and a pro-inflammatory cascade among multiple other mechanisms (Chen et al). Similar to other viral infections, COVID-19 and additionally vaccination against it may lead to flare of immune mediated diseases (Talotta et al) as what occurred in our second patient with predisposition to hypercoagulable state given his family history of systemic lupus erythematosus.